Energy guiding chain

ABSTRACT

For the purpose of improving the discharge of electrical charges via the energy guiding chain, an energy guiding chain ( 1 ) with a plurality of links ( 2 ), which are connected to each other in articulated fashion and each display opposite side pieces ( 3 ) and at least one cross-member ( 4   a ) connecting them, where the links ( 2 ) consist at least partly of an electrically conductive material that permits the discharge of electrical charges over at least part of the chain length, is characterized in that the links ( 2 ) are designed such that they are in contact with each other over the full pivoting angle on contact areas that move relative to each other and are in permanent contact and/or in that at least one connecting element ( 8 ) connecting two or more links to each other in each case is provided, which provides contact areas remaining in unchanging position in relation to the links, and in that the contact areas, and the areas of the links or the connecting element connecting them, form a continuous conductivity path with low electrical resistance, which extends at least over several links and permits use of the chain in ESD protection zones.

The invention relates to an energy guiding chain for guiding lines andcables between two consumers, at least one of which is mobile, where theenergy guiding chain displays a plurality of links displaying oppositeside pieces and at least one cross-member connecting them, where theindividual links are connected to each other by at least one pivotedconnection that permits pivoting of adjacent links through a pivotingangle relative to each other, such that the energy guiding chain can bearranged to form a lower run, a curved section and an upper run, andwhere the links consist at least partly of an electrically conductivematerial that permits the discharge of electrical charges over at leastpart of the chain length, and thus use of the chain in ESD protectionzones.

The ESD compatibility of the chain is designed to avoid electrostaticcharges in the chain, so that the energy guiding chain can be used insensitive areas, e.g. in the production, packaging or transportation ofelectrical or electronic components, such as semiconductor elements, orin explosion-protected areas. In this context, the energy guiding chainused must be electrically grounded in an appropriate manner, where, inparticular, the end fastening links of the energy guiding chain aregrounded, by means of which the chain is fastened to the consumers.

In energy guiding chains, the links are mostly connected to each otherby pivoted connections in the form of pin-and-hole connections, wherepivot pins projecting laterally on the side pieces of a first linkengage corresponding recesses on the side pieces of an adjacent link.However, it has been found on various occasions that the energy guidingchains known to date do not always fulfill the above-mentioned ESDrequirements, or not dependably enough, particularly when they are madeof a plastic material, even if the plastic material in itself displayssufficiently high electrical conductivity.

Therefore, the object of the invention is to create an energy guidingchain that can be used dependably at all times in ESD protection zones,or other zones with comparable requirements profiles, and permitsimproved discharge of electrical charges via the energy guiding chain.

According to the invention, the object is solved by an energy guidingchain in which the links are designed such that they are in contact witheach other over the full pivoting angle on contact areas that moverelative to each other and are in permanent contact and/or areconnected, at least in pairs, by a connecting element that providescontact areas remaining in unchanging position in relation to the links,and such that the contact areas, and the areas of the links connectingthem, form a continuous conductivity path with low electricalresistance, extending at least over several links, or over the wholechain. This permits use of the chain in ESD protection zones.

It has been found that the measures according to the invention arecapable of substantially increasing the dependability of an energyguiding chain in ESD protection zones, such that the chains can, inparticular, be used in ESD protection zones pursuant to EN 61340-5-1 orother, comparable technical standards. The measure according to theinvention ensures that the links are in permanent, electricallyconductive contact with each other over the full pivoting angle, suchthat electrical charges can be discharged across the links in thelongitudinal direction of the chain, and electrostatic charges can bereliably avoided. The contact areas assigned to adjacent links are thusin permanent contact with each other, or of continuous, one-piecedesign. In contrast, on chains with interlocking pin-and-hole pivotedconnections, the conductivity path is apparently interrupted innon-reproducible fashion owing to the potential play in the pivotedconnections. The electrical conductivity path extending continuouslyover several links or over the entire energy guiding chain, or the chainas a whole, can thus essentially or completely consist of a plasticmaterial, as a result of which—if necessary—metallic materials canadditionally be avoided entirely.

The continuous electrical conductivity path, which runs through theabove-mentioned contact areas and/or the connecting elements, which eachpreferably connect adjacent links to each other, advantageously extendsover the entire length of the energy guiding chain, preferably includingthe end fastening links of the chain. In this way, electrical chargescan be efficiently discharged over the entire length of the energyguiding chain. It may then be sufficient to ground only the two endlinks of the energy guiding chain, which can particularly be designed asend fastening elements and equipped with means for fastening to therespective consumers, or to provide them with grounding devices. Whereappropriate, the continuous electrical conductivity path can also extendover only part of the length of the energy guiding chain, particularlyif the links are grounded or connected to grounding devices at suitablepoints of the chain, to which end electrical connections for groundingdevices can be provided, for example. In particular, the entire area ofthe chain located between the end fastening links can provide acontinuous, preferably uninterrupted, conductivity path, separate endfastening links being provided in this context.

It goes without saying that, in the framework of the invention, thecontact areas can generally provide linear, or preferably plane, contactbetween the respectively adjacent links over the full pivoting angle, inwhich context the links preferably contact each other under force ofpressure in the contact area.

The contact areas of the links, which move relative to each other andprovide a continuous conductivity path, can be located in the area ofthe pivoted connections, or provided by the pivoted connections of thelinks. Thus, the contact areas can, for example, be located immediatelyadjacently to the pivoted connections, to which end an area projectinglaterally from the link can be provided that can be brought intopreferably plane contact with the adjacent link. Areas of this kind can,for example, be provided on the outer and/or inner sides of the sidepieces of the links.

According to an advantageous embodiment, at least one resilient tongue,which contacts the adjacent link under spring force over the fullpivoting angle of the links, can be provided on the pivot pin and/or onthe area of the link adjacent to it, which displays a recessaccommodating the pivot pin, as a contact area establishing electricalcontact. The resilient tongue can be integrally molded on the link. Tothis end, a part area of the pivot pin itself can, for example, bedesigned as a resilient tongue, for which purpose the pivot pin can beprovided with a slit at the end, or subdivided into several segments, atleast one of which, preferably all of which, contact the adjacent linkunder spring force. In this context, the resilient tongues can, inparticular, be designed as snap-in means that engage an undercut in thejoint receptacle of the adjacent link or its side piece. An area of theresilient tongue is preferably in plane contact with the adjacent link.

According to a further, alternative embodiment, which can, whereappropriate, be realized in addition to the embodiment of the pivotedconnections described above, an area that projects towards therespective adjacent link in the longitudinal direction of the chain andis in permanent contact with the side piece of the adjacent link overthe pivoting angle, is provided on at least one, or both, of the sideparts of the respective links as the contact area establishingelectrical contact. Correspondingly, an area that projects towards therespective adjacent link in the longitudinal direction of the chain can,for example, be provided on the cross-members of the links, being inpermanent contact with the side piece and/or the cross-member of therespectively adjacent link over the pivoting angle. The pivotedconnections of links of this kind can, for example, be provided by apin-and-hole connection described above, or by a strip-like joint hingethat connects at least two, preferably a plurality, or all links of theenergy guiding chain to each other, without being limited to this. Therespectively projecting areas can, for example, be designed in the formof tabs or webs. The cross-members can in each case be fastened to theside pieces in detachable fashion, or integrally molded.

Areas projecting towards the adjacent link in this way can preferably beprovided on both side pieces of a respective link, which surround theopposite side pieces of the adjacent link on the inside or on theoutside and are in contact with them under spring force. As a result,the links can in each case be constrained symmetrically between theareas making contact under spring force, this achieving reliableelectrical contact. Given suitable stiffness of the projecting areas,the lateral stability of the energy guiding chain can be increased atthe same time.

According to a further, advantageous embodiment, several or all links,preferably links that are immediately consecutive in the longitudinaldirection of the chain, are connected in pairs by at least oneconnecting element that is fixed in place by fastening areas, spacedapart in the longitudinal direction of the chain, on one of the links,where the connecting element is deformed elastically when the links arepivoted relative to each other. The connecting element is fixed on therespective links in its fastening areas, preferably in non-positivefashion and preferably in unchanging position, to which end therespective fastening area can be retained by a press fit in acorresponding receptacle of the respective link. In particular, fixingcan be achieved in non-positive and positive fashion. The receptacle forthe fastening area of the connecting element is preferably open in thelongitudinal direction of the chain, i.e. towards the respectivelyadjacent link, such that the connecting element practically bridges theadjacent links and is thus capable of providing a continuousconductivity path. The retention of the connecting element on the link,preferably by a press fit, guarantees a low contact resistance betweenthe links and the connecting element at all times.

It goes without saying that the receptacle for the connecting element onthe respective link can be designed as an opening of the side piecefacing towards the inside of the chain or the outside of the chain or,where appropriate, also towards the upper or lower narrow side of theside piece running in the longitudinal direction of the chain. Thisopening can essentially correspond to the contour of the longitudinalsection of the connecting element, such that the latter is inserted intothe recess from the side, or pressed in under force of pressure, inorder to be immovably fixed in place on the link. The connecting elementpreferably displays areas with a wider cross-section or areas with anarrower cross-section, which correspond to corresponding areas of thelink with a narrower cross-section or areas with a wider cross-section,and enable preferably linear or plane retention, as a result of which,in the longitudinal direction of the chain, the connecting element canalso be positively fixed in place in relation to the longitudinaldirection of the chain and, where appropriate, also in the transversedirection of the chain.

The elastic deformation of the connecting element during the pivotingmotion of the preferably adjacent links relative to each other can, inparticular, be performed in the manner of a bending stress, where themaximum deflection can correspond to the maximum pivoting angle of thelinks relative to each other. To this end, the connecting element mostlydisplays retaining areas, spaced apart in the longitudinal direction ofthe chain, for coupling the force on the links to be connected, and anarea located between them that is subjected to bending stress.

Alternatively, the connecting element can also be essentially exposed totorsional stress during elastic deformation. This is particularlypossible if the chain links each display laterally overlapping sideparts, in which recesses open towards the overlapping area of theadjacent link are provided, which are preferably aligned flush with eachother in the transverse direction relative to the chain. In thiscontext, the connecting element can be designed essentially in themanner of a cylinder, where the cylinder ends are located in oppositeoverlapping areas of adjacent links and can each be provided withnon-round areas to afford protection against rotation. Correspondingextensions can also be provided on the ends of the connecting elementfor this purpose. The middle area of the cylindrical connecting elementis then subjected to torsion when the links are pivoted. In thiscontext, the connecting element is preferably located entirely in thecross-sectional area defined by the two overlapping areas of adjacentlinks.

The connecting element is preferably designed as an elasticallydeformable element that, following elastic deformation, exerts arestoring force on the links connected by the element. It goes withoutsaying that all statements relating to the invention can also apply todeformable connecting elements that do not exert restoring forces on thelinks following deformation.

The connecting element can, particularly if it is exposed to bendingstress, be partly or completely located between the inner side of theside pieces, facing towards the inside of the chain, and the outer sideof the side pieces, facing towards the outside of the chain, or betweenthe lateral sides of the cross-members, such that it preferably does notproject laterally beyond the side piece or cross-member. In thiscontext, the connecting element can in each case be located between theupper side and the lower side of the respective link. As an alternative,the connecting element can also be located partly or completely in theinterior of the chain, e.g. between opposite inner sides of the sidepieces of a link, or in through-openings, running in the longitudinaldirection of the chain, in the upper or lower cross-members or sidepieces of the links. The width of the connecting element can, inparticular, correspond in each case to the width or thickness of theside piece or the width of the cross-member, i.e. its extension in thetransverse direction of the chain. In this context, the connectingelement can in each case connect two, or also three or more, links ofthe chain to each other and, for example, extend over one-quarter of thechain, one-half of the chain, or the entire chain. Between thepreferably elastically deformable areas of the connecting element, whichare spaced apart in the longitudinal direction of the chain, theelastically deformable connecting element can display transitional areasthat each extend between the deformable areas and connect them to eachother. The transitional areas can, for example, pass by on the outerside of the links, or extend through through-openings or grooves in thelinks, running in the longitudinal direction of the chain, which can,where appropriate, also be designed to be open towards one side.Referred in each case to the cross-section of the chain, thetransitional areas are preferably narrower than the joint areas of theconnecting elements.

In general, and particularly in the embodiments described above, theconnecting element can in each case constitute the joint element thatforms the articulated connection between adjacent links and absorbs theforces transmitted between the links during movement of the chain,particularly tensile and lateral forces. Alternatively or additionally,the connecting element can, in relation to the pivoted connections, alsobe provided in the form of an additional device and, to this end, befastened on the links in such a way that the forces acting when thechain moves are essentially absorbed by other areas of the chain. Inthis case, the device is essentially used for electrical discharge only.The connecting element can, for example, be designed as a strand-likeconnecting element that is fastened to several links and moves relativeto the respective link, or displays moveable areas, e.g. is fastened tothe link in the manner of a slipping clutch, or displayslength-compensating or expanding areas. This device can, whereappropriate, again be integrally molded on parts of the links, e.g. thecross-members or the side pieces.

The contact areas and/or the connecting elements of the links forproviding a continuous electrical conduction path can in each case beintegrally molded on at least one, of both, of the two links that areelectrically connected by the contact area or the connecting element.The contact areas and/or the connecting elements can also be fastened toboth links in detachable fashion.

Generally, one or more connecting elements can be provided in each case,which connect more than two links to each other, e.g. three, four ormore links, or extend continuously over at least one-quarter of thechain, at least one-half of the chain, or the entire chain in thelongitudinal direction. Preferably, the connecting elements also in eachcase establish an electrically conductive connection between the endfastening links, which can be grounded or provided with groundingdevices, and the respectively adjacent chain links. The electricallycontacting contact areas or connecting elements acting between thelinks, or also other contact elements, can be provided for this purpose.Further, grounded chain links or links with grounding devices, e.g. inthe form of a fastening for an electrical discharge device, can beprovided within the chain, i.e. adjacent to the end fastening links ofthe chain, or at a distance from them. The distance is preferablyseveral links, e.g. one-quarter of the chain or more. The connectingelement then preferably extends continuously from one grounded link, ora link connected or connectable to a grounding device, to another suchlink, or to an end fastening element of the chain, which is likewisepreferably grounded, or provided or fittable with a grounding device,such that a continuous electrical conductivity path is provided in theseareas. Electrical charges can then be rapidly discharged via therespectively grounded links.

Where appropriate, two or more connecting elements can also be provided,which interconnect a given group of more than two links.

In particular, the connecting element that enables electrical dischargeand interconnects several links in articulated fashion, can be ofstrip-like design, where the links can be fastened to or on the stripsuch that the strip is preferably only fastened to the links on oneside. The connecting element can be located inside or outside the ductfor guiding the electrical lines. The width of the connecting elementcan roughly correspond to the extension of the bottom elements of thelinks transverse to the chain, or the width of the links. In thiscontext, the strip-like connecting element can be fastened on the upperside of the bottom elements of the links, i.e. facing towards theinterior of the chain, or on the side of the bottom elements of thelinks that faces away from the interior of the chain, or, whereappropriate, be passed through slits or retaining areas of the bottomelements or the side pieces. The strip can also be fastened on thenarrow sides of the side pieces.

The connecting element can, particularly if it designed as a stripextending over several links or the entire chain, be fastened to thelinks in detachable fashion, e.g. by means of suitable snap-inconnections, although the links can also be inseparably fastened to thestrip or integrally molded on it.

Further, the electrically conductive connecting element can, forexample, be designed as a film hinge, by means of which adjacent linksare connected to each other in articulated fashion. In this context, theconnecting element can be located on the side pieces or the bottomelements, e.g. on the face ends of the same that face towards theadjacent link. Particularly also in this embodiment, the links can beprovided with lateral areas that project towards the adjacent link andpartially overlap it, e.g. on the inner side or the outer side of theside pieces. It goes without saying that, where appropriate, these areascan additionally be designed as electrically conductive connecting areasthat are in contact with the side pieces of the adjacent links underpermanent force of pressure over the full pivoting angle of the links.Independently of this design, it is, however, advantageous if thecontact areas and/or the connecting elements of electrically conductivedesign contact the respectively adjacent link under force of pressure.

The contact areas and/or the connecting elements can in each case bemade of the same material as, but also of a different material than, theother areas of the links, e.g. the side pieces or bottom elements,particularly of a material having greater conductivity.

The contact areas and/or the connecting elements of the links,particularly the areas of the energy guiding chain that form acontinuous conductivity path and encompass said contact areas and/orconnecting elements, preferably consist of a material with lowresistivity. This enables particularly effective discharge of electricalcharges from the energy guiding chain. The side pieces and/or bottomelements of the links preferably consist entirely of a material of thiskind, particularly a plastic material.

The total resistance of the energy guiding chain over its entire lengthis preferably less than/equal to 50,000 ohm or 20,000 ohm, preferablyless than/equal to 10,000 ohm, particularly preferably 10,000 ohm to6,000 ohm, or also less. This particularly applies to energy guidingchains in which the links and the connecting elements consistpredominantly or entirely of a plastic material.

Further, the energy guiding chain according to the invention candisplay, over its length, an electrical surface resistance R_(s) and/oran end-to-end resistance R_(e) and/or a point-to-point resistance R_(p)of ≦1×10¹⁰ ohm, preferably ≦1×10⁶ ohm or ≦1×10⁴ ohm in each case, forexample in the range 1×10⁴≦R_(p)≦1×10¹⁰ ohm.

Additionally or alternatively, the energy guiding chain according to theinvention is designed such that it displays an electrical resistance toEPA ground and/or to a grounding point R_(g) of ≦1×10¹² ohm, preferably≦1×10⁹ ohm. The above-mentioned resistance is preferably in the range7.5×10⁵≦R_(g) ≦1×10⁹ ohm.

The values given above for the total resistance, surface resistanceR_(s), end-to-end resistance R_(e) and/or point-to-point resistanceR_(p), resistance to EPA ground or to a grounding point, preferablyinclude the end fastening elements in each case. The respectivelymentioned electrical resistance can in each case also exist between twolinks that are each grounded by a suitable electrical, preferablymetallic, discharge device, or provided with a suitable grounding deviceor a preferably electrically conductive fastening means for such adevice. In the simplest case, the grounding device can be a connectingpoint designed for electrical connection of an electrical dischargedevice. The links that are grounded, or provided with grounding devicesor fastening means for such devices, are preferably distributeduniformly over the length of the line guiding device.

It goes without saying that the energy guiding chain can meet all otherrequirements to DIN EN 61340-5-1, or corresponding national orinternational standards. In this context, the chain can, whereappropriate, be taken as being a work surface pursuant to Table 1 ofthis European Standard. It goes without saying that the respectivedetermination of the resistances mentioned can likewise be performedaccording to this standard. Reference is made to Section 5.3 of EN61340-5-1:2001, regarding the requirements for an EPA grounding deviceor an EPA ground terminal, to Section A.1 of EN 61340-5-1:2001 regardingthe resistance measurement method for testing work surfaces, to AppendixA.1 of DIN standard IEC 1340-4-1 regarding the device for resistancemeasurements, and to DIN 53482 or DIN IEC 60093 regarding the design ofelectrodes for measuring the respective resistances. All theabove-mentioned standards are herewith included as references. It goeswithout saying, however, that other pertinent standards can also beused, where appropriate.

In order to provide a material with sufficiently high electricalconductivity, the surface of the respective links, including the surfaceof the bottom element connecting several links to each other, which canin each case particularly be manufactured as plastic parts, can beprovided with a conductive coating, e.g. with a graphite coating or acoating of a metallic or semiconducting material, for example also bygalvanization, vaporization methods or the like. Further, as analternative or in addition, volatile antistatic agents can beincorporated into the material of the line guiding device, particularlyin the area of the side pieces and/or the bottom element, or in thecontact areas or on the retaining areas of the connecting elements.Particularly preferably, the material intrinsically displayscorresponding volume conductivity or surface conductivity in order tomeet the above-mentioned conditions, to which end the plastic materialcan, for example, be provided with corresponding fillers that increasethe electrical conductivity, such as carbon fibers, fibers of metallicor semiconducting materials, metallic or semiconducting powders, such asaluminum or silicon powder, carbon black, salts, such as lithium salts,or the like. Finally, discharge wires, such as metallic discharge wires,can be incorporated into the bottom element, also extending over theconnecting elements and/or several links, or the entire chain. It goeswithout saying that the corresponding conductivity can also be createdin some other suitable way.

Seen as a whole, it is thus possible to provide a line guiding devicefor ESD protection zones (ESD: electrostatic sensitive device) and/orfor explosion-hazard areas.

An example of the invention is described below and explained on thebasis of the Figures. The Figures show the following:

FIG. 1 A perspective representation (FIG. 1 a) and a side view (FIG. 1b) of a first embodiment of an energy guiding chain according to theinvention,

FIG. 2 A cross-sectional view (FIG. 2 a) and a side view (FIG. 2 b) of afurther embodiment of an energy guiding chain according to theinvention,

FIG. 3 A perspective representation of a further embodiment of a chainaccording to the invention,

FIG. 4 A side view (FIG. 4 a) of a further embodiment of an energyguiding chain according to the invention, and front and side views of achain link (FIGS. 4 b, 4 c),

FIG. 5 A top view (FIG. 5 a) and a side view (FIG. 5 b) of a furtherembodiment of a link of a chain according to the invention.

FIG. 1 shows, in a first embodiment, an energy guiding chain 1 accordingto the invention, with a plurality of links 2, which are connected toeach other in articulated fashion and each consist of two opposite sidepieces 3, at least one cover element 4 a in the form of a cross-memberconnecting the two side pieces to each other, and at least one bottomelement 4 b in the form of a further cross-member. According to thepractical example, only some of the links are equipped withcorresponding bottom elements and cover elements, in order to separatethe two opposite strands of side pieces from each other. The energyguiding chain is arranged to form an upper run 5, a curved section 6,and a lower run 7. The individual links 2 are connected to each other inarticulated fashion by separate connecting elements 8, which arepreferably fastened in detachable fashion, are subjected to bendingstress during traveling motion of the chain, and can be deformedelastically, developing a restoring force.

Side pieces 3, particularly the areas between adjacent connectingelements 8 of a side piece, and also the connecting elements, consist ofa plastic material with high electrical conductivity. It goes withoutsaying that bottom and cover elements 4 a, 4 b preferably also consistof a material of this kind.

Connecting elements 8 are retained in recesses 11 in side pieces 3,which are designed to be open towards face end 11 a, i.e. towards theadjacent link. Further, recesses 11 are designed to be open at leasttowards one lateral surface, towards both lateral surfaces according tothe practical example, such that connecting elements 8 can be insertedlaterally into recesses 11. Connecting elements 8 display widerfastening areas 15, which engage the area with a wider cross-section 14of recess 11, in order to guarantee positive retention of the connectingelements in this way when tensile force is exerted in the longitudinaldirection of the chain. It goes without saying that a positive fit canalso be achieved in some other suitable way. Independently hereof, theconnecting elements are similarly retained in recesses 11 innon-positive fashion to secure them against lateral displacement, towhich end the connecting elements have to be forced between jaws 14 aand into the recesses by applying force of pressure, this simultaneouslyestablishing good electrical contact between the components. Additionalmeans can be provided to secure the connecting elements in thetransverse direction. Elastic deformation of the connecting elements isfacilitated by the fact that a cut-out 16 in the links is providedbetween opposite recesses 11 at the height of deformable area 12, saidcut-out being of roughly semi-circular design in this instance.

According to FIG. 1, connecting elements 8 can each extend over severallinks in the longitudinal direction of the chain, to which endtransitional areas 8 a are provided between fastening areas 15, thewidth of which is smaller than that of areas 12 subject to elasticbending stress, which can have the width of the side pieces. As aresult, connecting element 8 can also extend over the full length of thechain and provide a continuous conductivity path. The transitional areasare thus located in grooves (represented by broken lines) provided inweb-like areas 24 a of the links.

Because of the bending stress, connecting elements 8 can consist of adifferent material than the side pieces. The connecting elements canconsist of a material with higher electrical conductivity than that ofthe links, especially since the total length of the connecting elementsexceeds the longitudinal extension of web-like areas 24 a in thelongitudinal direction of the chain. Overall, this means that connectingelements 8, and web-like areas 24 a of the links remaining between them,provide a continuous electrical conductivity path for the chain, viawhich electrical charges can be discharged, with little electricalresistance, to the end fastening elements or end links of the chain,which are grounded, or to other grounded links of the chain. The jointelements, preferably including their connecting areas if the jointelements extend over several links or the entire chain, may have beenrendered electrically conductive, particularly by means of surfacetreatment methods, e.g. by galvanization, vaporization, particularlywith metals or semiconducting materials, or the like. This also appliesaccordingly to other embodiments of the chain according to the inventionwith separate joint elements, e.g. in the form of strips. However, it isalso possible for part areas of chains of different design to besurface-treated accordingly in order to provide a continuous electricalconductivity path.

The side pieces of the links furthermore display overlapping areas 17,which are provided with laterally protruding projections 18, which cansimultaneously serve as stops. Projections 18 engage correspondingopenings in the adjacent links, which are open towards the overlappingarea of the adjacent link. Where appropriate, these overlapping areascan be in contact with each under permanent force of pressure over theentire pivoting angle, to which end, for example, projections 18protrude sufficiently far in the axial direction. Given a suitablechoice of material for the respective areas, this also makes it possibleto establish electrical contact between adjacent links that is preservedthroughout the entire pivoting movement of the links. Owing to theresultant increase in friction losses during movement of the chain, ameasure of this kind may also be dispensable, although it can also berealized as an alternative to an electrically conductive design of theconnecting elements.

FIG. 2 shows a further practical example of a chain 20, which displays aplurality of links 21 that are fastened on a strip-like joint element22. Forming a cable guide duct 20 a, the links here again each displayopposite side pieces 23, and a bottom element 24 connecting them, whereupper cover element 25 is designed as a perforated cross-member.Strip-like joint element 22 again provides a continuous electricalconductivity path, to which end the material forming the strip has highelectrical conductivity, which can be higher than the conductivity ofthe link material, although this is not always necessary. The links or,more precisely, the undersides of the bottom elements and/or the sidepieces are fastened on the strip here under a certain force of pressure,providing electrical contact areas. To this end, the strip is providedwith snap-in projections 26, which engage recesses 26 a in the bottomelements, which are provided with an undercut, and press the linksagainst the strip under a certain pre-tension. It goes without sayingthat, where appropriate, the snap-in projections can also be provided onthe bottom elements, and corresponding snap-in recesses on the strip. Inaddition to the snap-in means with the snap-in receptacles, contactareas according to the invention between the strip and the link are, asalso in the other, similar embodiments, moreover also provided by thesides of the cross-members or bottom elements facing the strip, whichcan be the side facing towards or away from the guide duct, and thecontact surface of the strip.

Further, the links display lateral guide elements 29, which reach aroundpartial areas of the side parts of the adjacent links and, to this end,engage pockets 29 a in the same, and can make lateral contact with theside pieces of the adjacent links, under a certain pre-tension whereappropriate, in order to enable electrical discharge of charges via theguide elements, additionally or alternatively to the strip. However,these guide elements are primarily intended to increase the lateral ortransverse stability of the chain, and to provide stops by means ofprojections 27, where appropriate, these engaging lateral projections 28of the side pieces. It goes without saying that strip 22 can extendcontinuously and in one piece over the entire length of the chain,although two or more strips can also be arranged consecutively, whereappropriate. In the latter case, the link connecting two strips is thenpreferably likewise made of a material with high electricalconductivity, or an additional electrical bridging contact is provided.

FIG. 3 shows a chain 30, constructed similarly to that in FIG. 2, wherethe individual links 31 of the chain are, however, connected to eachother by integrally molded joint elements 32. Again, at least some, orall, of the links 31 display opposite side pieces 33 and a bottomelement 34 connecting them, as well as a cover element 35, thus forminga cable guide duct. Together with the bottom elements, joint elements 32form a continuous strip, where the joint elements can be designed in themanner of film hinges, but can also have the material thickness of thebottom elements, to which end side pieces 33 are spaced a small distanceapart in the joint area. The chain can be produced in one piece over itsentire length. Where appropriate, it is also possible for severalsegments, each designed as one piece and extending over a plurality oflinks, to be connected to each other. The entire chain, or theindividual segments, can in each case be made of a single materialdisplaying high electrical conductivity, as described in connection withthe first practical example. In this instance, the chain is manufacturedas a one-piece injection molding, although extruded parts can also bedesigned correspondingly as a chain, where appropriate. The links candisplay a certain stiffness, such that they are essentially rigid undernormal operating conditions, although this is not always compulsory.

FIG. 4 shows a further embodiment of chain 40 according to theinvention, where the individual links 41 each display side pieces 42with areas 42 a, which project from the face end and overlap theadjacent link. The links are fastened on a flexible strip 48, by meansof snap-in means according to the practical example, to which endsnap-in projections 48 a on the strip can engage recesses 41 a in thelinks. The upper and lower ends of overlapping areas 42 a are eachprovided with arc-shaped sections 43, 44, which additionally serve aslateral guides for the adjacent link during the pivoting movement. Avertical offset between adjacent links is prevented by projections 45,46 on the side pieces of the adjacent links, which reach over or underarc-shaped sections 43, 44.

It goes without saying that joint hinge 48 can display high electricalconductivity, providing a conductivity path, in which context the stripcan extend over the full length of the chain, or two strip segments canbe fastened in unchanging position on a link with high electricalconductivity, e.g. by the snap-in means, particularly under force ofpressure against the strip, such that the undersides of the bottomelements and/or of the side pieces act as electrical contact areas. Thelinks can be fastened to the strip in detachable or non-detachablefashion. Where appropriate, however, the strip can also be absent, towhich end elastic projections can be integrally molded on the bottomarea of a link, reaching below the bottom area of the adjacent link. Inthis case, a continuous electrical conductivity path can, for example,be provided by one of both of the arc-shaped sections 43, 44 beingguided in close contact on the corresponding projection, particularlyunder force of pressure, and at least the corresponding sections 44 and46 or 43 and 45 of the side pieces and the connecting areas between them(or also the entire side pieces or entire links) consisting of amaterial with high electrical conductivity. Contact areas 44, 46 areconnected to each other in electrically conductive manner by web-likearea 46 a or the side piece. This would preferably apply to thearc-shaped areas adjacent to joint axes 47. Force of pressure ofarc-shaped section 44 on the likewise arc-shaped surface of projection46, these two being guided on each other over the entire pivoting angle,can particularly be generated by strip 48 (or a correspondingly designedtab that only reaches under the adjacent link), by means of which links41 are pressed against each other in a direction perpendicular to thelongitudinal direction of the strip and parallel to the side pieces. Inthis context, the force of pressure can be generated by snap-in means 48a for fastening the links on the strip, particularly if snap-fitting isaccomplished under pre-tension of the links relative to the strip. Itgoes without saying that, referred to the conductivity path viaarc-shaped areas 44, 46, the strip can simultaneously or alternativelythus consist of a material with high electrical conductivity.

FIG. 4 shows, in schematic form, examples of two links designed asgrounded links 41 b, which are connected to ground in electricallyconductive fashion. It goes without saying that the electrical dischargelines to ground can also be routed along the chain. The specifiedresistance of approx. 10,000 ohm can thus also be present between links41 b. Links 41 b are then connected to each other by a continuousconduction path, e.g. in the form of a continuous strip 48. Arrangementsof this kind are possible with very long chains, in particular. It goeswithout saying that the same also applies to the other practicalexamples.

FIG. 5 shows a further embodiment, where only one link 51 of an energyguiding chain is illustrated. The links are each connected by means ofpivoted connections, in which pivot pins 53 on one side piece 52 of afirst link engage pin receptacles 55 on the side pieces of therespectively adjacent link. The side pieces are connected by at leastone cross-member 57. Pivot pins 53 each display resilient tongues 54,the electrically contacting contact areas 58 of which contact inner side56 of the pin receptacle of the adjacent link under a certain force ofpressure over the entire pivoting angle of the links. To set the forceof pressure and to avoid seizing of the pivoted connections, pins 53 aredivided into at least two, e.g. three, segments by notches. The pins canadditionally be designed as hollow pins to this end. It goes withoutsaying that the pins can also pass completely through the opposite sidepieces and contact their outer sides. At least the pivot pins and theareas of the pin receptacle are made of a material with high electricalconductivity, where the connecting areas of the pivot and the receptacleof each link should likewise display high electrical conductivity inorder to form a continuous conductivity path.

It goes without saying that the embodiments illustrated can always bemanufactured as plastic moldings. In particular, the chains or theirlinks can in each case be manufactured as injection moldings.

The chains according to the practical examples each display, over theirentire length, an electrical resistance of less than/equal to 20,000ohm, more precisely approx. 6,000 ohm to 10,000 ohm. In this context,the chain length can be half a meter or a meter, or longer, e.g. even 10meters or more.

LIST OF REFERENCE NUMBERS

-   1 Energy guiding chain-   2 Link-   3 Side piece-   4 a Cover element-   4 b Bottom element-   5 Upper run-   6 Curved section-   7 Lower run-   8 Connecting element-   8 a Transitional area-   11 Recess-   11 a Face end-   12 Flexurally elastic area-   14 Area of wider cross-section-   15 Fastening area-   16 Cut-out-   17 Overlapping area-   18 Projection-   20 Chain-   21 Link-   22 Joint element-   23 Side piece-   24 Bottom element-   24 a Web-like area-   25 Cover element-   26 Snap-in projection-   27 Projection-   28 Axial projection-   29 Guide element-   30 Chain-   31 Link-   32 Joint element-   33 Side piece-   34 Bottom element-   35 Cover element-   40 Chain-   41 Link-   41 a Recess-   42 Side piece-   42 a Overlapping area-   43, 44 Arc-shaped section-   45, 46 Projection-   47 Joint axis-   48 Strip-   48 a Snap-in projection-   49 a Grounded link-   50 Chain-   51 Link-   52 Side piece-   53 Pivot pin-   54 Resilient tongue-   55 Pin receptacle-   56 Inner side-   57 Cross-member-   58 Contact area

1. Energy guiding chain for guiding lines and cables between twoconsumers, at least one of which is mobile, where the energy guidingchain displays a plurality of directly adjacent links connected to eachother in articulated fashion, each of which displays opposite sidepieces and at least one cross-member connecting them, forming a cableguide duct, where the individual links are connected to each other by atleast one connecting element that permits pivoting of adjacent linksthrough a pivoting angle relative to each other, where the energyguiding chain can be arranged to form a lower run, a curved section andan upper run, including end fastening links, and where the links consistat least partly of an electrically conductive material that permits thedischarge of electrical charges over at least part of the chain lengthand said chain provides electrostatic discharge compatibility,characterized in that directly adjacent links are connected to eachother by at least one connecting element and contact areas are providedbetween said directly adjacent links, said contact areas comprising atleast one arc-shaped section of one link which is in contact with aprojection of a directly adjacent link, and in that the connectingelement extending between said directly adjacent links and said contactareas form a continuous conductivity path with low electricalresistance, which extends at least over several links and wherein atleast one of the links that are located between the end fastening linksof the chain, or also encompass them, is grounded, or connected to agrounding device, or fitted with means for electrically conductiveconnection to a grounding device.
 2. Energy guiding chain according toclaim 1, characterized in that the continuous electrical conductivitypath extends over the entire length of the energy guiding chain. 3.Energy guiding chain according to claim 1, characterized in that thelinks and/or the at least one connecting element display lowresistivity.
 4. Energy guiding chain according to claim 1, characterizedin that the contact areas of the links that move relative to each otherand provide a continuous conductivity path between adjacent links, areprovided by areas adjacent to the pivoted connection or by the pivotedconnections of the links.
 5. Energy guiding chain according to claim 1,characterized in that said projection is provided, at least on one, orboth, of the side pieces of the links, being in contact with thearc-shaped section of the adjacent link over the pivoting angle. 6.Energy guiding chain according to claim 5, characterized in that areasprojecting towards the adjacent link are provided on both side pieces ofa respective link, which both surround the opposite side pieces of theadjacent link on the inside or on the outside and have at least partialareas in contact with the respective side piece under spring force. 7.Energy guiding chain according to claim 1, characterized in that theconnecting element connects several links to each other, forming acontinuous conductivity path.
 8. Energy guiding chain according to claim7, characterized in that the connecting element extends over the entirelength of the energy guiding chain, and in that the connecting elementprovides the pivoted connection connecting the links to each other inpairs.
 9. Energy guiding chain according to claim 1, characterized inthat the connecting element is a flexible strip, and in that the linksare fastened to or on the strip.
 10. Energy guiding chain according toclaim 1, characterized in that the contact areas of one link and/or theat least one connecting elements contact the adjacent link under forceof pressure.
 11. Energy guiding chain according to claim 1,characterized in that the links and/or the connecting elements at leastessentially consist of a plastic material.
 12. Energy guiding chainaccording to claim 1, characterized in that an end link on at least oneend, or both ends, of the energy guiding chain is designed as an endfastening element and provided with fastening means for fastening theenergy guiding chain on a consumer, and in that the end fastening linkis connected to the respectively adjacent link via an electricalconnection.
 13. Energy guiding chain according to claim 1, characterizedin that, over its entire length, or over a distance in the longitudinaldirection of the chain between two adjacent links that are grounded, orprovided with a grounding device, or with fastening means for such adevice, the chain displays an electrical resistance R of approx. 50,000ohm or less and/or an electrical surface resistance R_(s) and/or anend-to-end resistance R_(e) and/or a point-to-point resistance R_(p) of≦1×10¹⁰ ohm.